Instrument Cluster Voltage regulator

[DAYLEY/CHALLENGER]

May be a question that may  be simple or if I thought about it long enough would I still ask it.  Anyway, I cannot get the oil pressure or the temp guage to give a readout (Rally panel).  I have checked around and I can get a regulator but I think the one I have is ok.  I hooked up 12 volts to it and it gave the  5 volts out.   Now the question.   I do not at this time have the fuel sending unit hooked up.  I think these three guages are all looped together. By not having the fues guage in the loop, Am I leaving a gap in the electrical circuit?   There I asked the   Thanks in advance.  David

[Super Blue 72]

My guess is that the other gauges should still work because they are individually grounded.  I don't think I've heard about someone's Rallye dash gauges all 3 not working because they had one bad gauge or something.  I could be wrong though.... 

You are correct to say that these three gauges are looped together in that one wire comes off the voltage limiter, runs to the oil gauge, then the temperature gauge, then finally to fuel gauge.  This is the positve only, as they are "hooked together" in series by connectors at each gauge, each gauge should have it's own individual sending unit.

Make sure that the wire coming off the voltage limiter has continuity all the way through to the end where it connects with the fuel gauge.  You may (I'm not sure but just a hunch  ) want to test each gauges individual ground at the gauge also to make sure that the "POS" juice has a place to go.  They have individual, separate grounds according to the FSM that lead to the bulkhead connecter.

Hope this helps! 

[MEK-Dangerfield]

Electrical questions perk me up, so I am here to guess until I get it right. 

The gas gauge is the last in the daisy chain wiring coming from the voltage limiter, so it doesn't matter if that isn't connected at this time. Are you testing the gauges with the gauge pod screwed in to the dash for the ground connection? Can you post a pic of these 3 gauges, as they might have all been fried. You can tell this if all the needles are hanging low.


  Mike

[Bullitt-]

You should be able to use a 6-12volt dry cell battery or other DC source to test each gauge

     from http://rt-eng.com/mediawiki/index.php/RTE_Gauge_Faq#General_guidelines_to_gauge_testing_on_vintage_mopars

On the Fuel/oil/temp gauges, put 9V or 12V across them for 1 second, and if the hands move then they are good. (This does not test the calibration, but that is more complicated). DO NOT leave the 12V on the gauges for more than 1 second.




Test the limiter by putting 12V into it, grounding the limiter case, and seeing if the output goes off and on and off every 1-2 seconds, using a test light. If it is stuck on 12V, then the limiter is bad and it will fry your fuel/oil/temp gauges.




Take the ammeter out of the housing, and look and see if it has any corrosion on it (do NOT use a corroded one in a car, it can catch on fire). Also gently wiggle the two studs, and if either stud moves, DO NOT use this ammeter in your car as it can catch on fire. I can rebuild these if you have a bad one. Also, make sure that the needle points to zero as you tilt the ammeter around. If the needle moves and points far to the left and right, then the magnet in the ammeter is bad and you need a new ammeter.

[MEK-Dangerfield]

Aaaw, what the heck,

Pics of the wiring, and of working gauges. The 12 volt feed plugs into the lowest tab on the voltage limiter.


  Mike

[Super Blue 72]

Mike, you are awesome! 

[MEK-Dangerfield]

Mike, you are awesome! 

If only you were a girl...   

[71bigblock]

If only you were a girl...   

Ba-dum-sshhh

[Super Blue 72]

If only you were a girl...   

Sorry to disappoint you...     

[DAYLEY/CHALLENGER]

OK.  I know my relay is now working.   Put 12 volts to it and was getting the pulse voltage out.  Decided to check my guages again.  Negative wire, simulating the sensor wire, to the sensor post.   Positive 12 volts to the post that received the pulse voltage. Only for a second....... all the guages worked. .   Now I realize that the  limiter hasn't been getting voltage.  I got to go thru all the wiring in the dash anyway because I wasn't getting any dash lights either.   Now the time consuming task.   Thanks all for the help.

[Chryco Psycho]

Dash lights are usually either a ground problem with the upper panel or a bad dimmer switch [not headlight dimmer on the floor ]

[Super Blue 72]

... a bad dimmer switch [not headlight dimmer on the floor ]

   My dash lights didn't work and I kept working the dimmer switch (next to the headlight switch) back and forth and that I guess helped to clean the contacts and the dash lights now work in my particular situation.

[larry4406]

I agree on the instrument dimmer.  Mine died, no dash lights.  I made a jumper out of a piece of copper stripped wire and jumpered the socket feeding the dimmer.  Full bright all the time, dimmer in position looking like it does something.  Did this almost 20+ years ago, not sure how I did the jumper.

[MEK-Dangerfield]

I agree on the instrument dimmer.  Mine died, no dash lights.  I made a jumper out of a piece of copper stripped wire and jumpered the socket feeding the dimmer.  Full bright all the time, dimmer in position looking like it does something.  Did this almost 20+ years ago, not sure how I did the jumper.

Nice move. 

I wasn't so creative. I replaced my bad dimmer with a toggle switch. You have to look hard to notice it on my dash panel, so I don't get too much crap.  The good news is it makes my dashlights much brighter than anyone who still is useing the original dimmer switch.


   Mike